Radio communication devices, such as mobile stations which communicate via radio frequency (RF) signals, are typically portable and powered by removable batteries. A removable battery can supply power to a communication device for a limited amount of time which is inversely proportional to an average power consumption of the device. Thus, it is often desirable to decrease the power consumption of a communication device in order to increase its operating time before the batteries are depleted. Alternatively, it is often desirable to decrease the power consumption in order to decrease the size of the removable battery that attaches to the communication device.
Intermittent receive (IRX) methods, where typically a receiver of a communication device is powered off during some portion of a receive time period, are known. However, these methods are generally more difficult to apply to devices operating in a time division multiple access (TDMA) system because of its inherent complexities. For example, a communication device operating in a TDMA system must quickly alternately receive and transmit data in adjacent time slots, and receive peripheral zone signals and measure signal strengths thereof in between such slots. Electrical circuitry of a communication device, which typically includes a receiver, a transmitter, a synthesizer, a digital signal processor, and a microprocessor, needs to be powered on for most such processing. Because of relatively slow response and settling times of electrical circuitry, it may not be practical to power off circuitry that will need to be powered on soon thereafter.
Accordingly, there is a need to reduce a power consumption of a communication device, especially a radio communication device that operates in accordance with TDMA schemes.